Polar Vortex arrives but its 2nd wave may be even more brutal

The upper Midwest is in the deep freeze, with the arctic air expected to shift eastward as the week wears on. The National Weather Service posted advisories for the Dakotas and Minnesota, with wind chills from 10 to 20 below zero. (Dec. 13)
AP

Thanks to another unwelcome visit from the Polar Vortex, dangerous, life-threatening cold temperatures and fierce winds will spread across much of the Midwest and Northeast over the next several days.

A snowstorm will also add to the wintry misery for parts of the northern U.S. with blizzard conditions possible in some areas.

The cold will come in two waves, the first Wednesday and Thursday and the second — which could be even more brutal — over the weekend.

Some locations could experience their coldest December temperatures in several years, the Weather Channel said, and a few record lows may be threatened.

The beleaguered northern Plains and Upper Midwest will again bear the brunt of the icy onslaught: "Dangerous to life-threatening" wind chill temperatures to 45 below zero are forecast Friday night through Sunday morning in parts of the Dakotas, the National Weather Service said.

Wind chills this cold can cause frostbite in less than 10 minutes, the weather service said.

The fierce cold is thanks to the Polar Vortex, which is seeping down from its rightful place in the Arctic. Though the vortex has been around for a few billion years and understood by scientists for several decades, it only entered the popular lexicon as a synonym for miserably cold weather a few years ago.

First blast

The first assault is spreading across the northern Plains and Midwest on Wednesday, where temperatures by Thursday morning will dip below zero in cities such as Minneapolis and Milwaukee.

A wind chill temperature of 38 degrees below zero was recorded Wednesday morning in Langdon, N.D., according to the weather service.

The weather service issued a wind chill advisory Wednesday for all of North Dakota, Minnesota and Wisconsin, and parts of Montana, Wyoming, South Dakota, Iowa, Illinois, Indiana, Ohio and Pennsylvania.

Below-zero wind chills are likely for most of those areas for much of Wednesday and into Thursday.

The cold will finally make it to the Northeast and Mid-Atlantic by Thursday. Temperatures will not rise out of the 20s along the Interstate 95 corridor, from Boston to Washington D.C., on Thursday and Friday, the Weather Channel predicts.

Second blast

A second round of hideous cold, perhaps even more intense than the first blast, will dive into the central U.S. on Saturday and Sunday.

Below-normal temperatures are likely this weekend and into Monday across the entire northern half of the country, from the Pacific Northwest to Maine and as far south as Texas, Arkansas and Virginia, the Climate Prediction Center said.

Afternoon readings won't rise above zero in the northern Plains, upper Midwest and western Great Lakes both weekend days, including Minneapolis and Fargo, N.D.

Chilly temperatures will reach down all the way to Texas. After seeing temperatures near 70 degrees on Saturday, the high temperature in Dallas on Sunday will only be near freezing.

The Northeast and Mid-Atlantic will be dealt a glancing blow from this cold blast by early next week.

The good news is that moderating temperatures are forecast for much of the central and eastern U.S. just before Christmas, AccuWeather said.

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